3.90 and true trac

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09-06-2008, 11:32 AM
banker099

3.90 and true trac

im at work right now but i will be swapping my 3.42 & open diff for a set of 3.90 and a true trac when i get off, probly gonna start about 2p.m.

any tips/tricks before i start?

whats the estimated time this swap should take?

heres what i got gears and install kit true trac all from rons machine.
09-06-2008, 12:00 PM
PurpleMinivan

Measure, measure, measure, shim, measure, measure, shim....Your gonna like the truc trac and it's easy to install, :hyper2:No springs:hyper2:
09-06-2008, 12:14 PM
banker099

well...the gears have no instructions...

i should measure the "play" now and set the new gears to to same as what they are set to now right?
09-07-2008, 11:36 AM
GasGuzzler

There's a lot more to it than that. Do you have a repair manual, special tools, or experience with a gear swap?
09-07-2008, 12:08 PM
CHEVROLADE

Man U Actually Going To Do The Install Your Self?good Luck!!
09-07-2008, 02:51 PM
banker099

well...after 4 hours its done...put it in and took it out quite a few times before we finally got it where i liked it...which ended up being .005...

oh, and it would been nice to know that the bolts that keep the ring on the carrier are reverse thread, i could NOT figure out why those bolts wouldnt start threading in!!

oh, and now my speedo is way off and im in overdrive at like 30mph now, hopefully my tune will be here mon or tues :)
09-07-2008, 02:54 PM
banker099

Quote:

Originally Posted by GasGuzzler

There's a lot more to it than that. Do you have a repair manual, special tools, or experience with a gear swap?

no repair manual...but the old man's (my dad) experience makes all the difference, along with having the right tools and a lift.

this was the first gm rearend we have done, had lots of experience on dana 30, 44, 35, and ford 9"

wasnt to bad but was time consuming!
09-07-2008, 05:57 PM
GasGuzzler

Glad to hear it. Experience was your ace in the hole.
09-08-2008, 12:41 PM
CHEVROLADE

good to hear,so how does the 3.90s work?
09-08-2008, 12:48 PM
banker099

Quote:

Originally Posted by chevrolade

good to hear,so how does the 3.90s work?

well...good so far...gm should seriously consider putting these gears in from the factory, especially on the v6 trucks, a lot more power on the bottom end, i have only put 50 miles on them so far and i havnt got on it, but i will post an update once they get broken in and i will start beating on them,

i did go to the carwash and gave it a little throttle and i will say turning right and sliding sideways feels kinda weird :lol: